package com.bilibili.juc.threadlocal;

import java.util.Random;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

/**
 * @author zuife
 * @description 需求：【强制】必须回收自定义的ThreadLocal变量，尤其在线程池场景下，线程经常会被复用，如果不清理自定义的ThreadLocal变量，可能会影响后续业务逻辑和造成内存泄漏等问题。尽量在代理中使用try-finally块进行回收。
 * @since 2024-05-05 16:10:43
 */
public class ThreadLocalDemo2 {
    public static void main(String[] args) {
        MyData myData = new MyData();
        ExecutorService threadPool = Executors.newFixedThreadPool(3);
        try {
            for (int i = 0; i < 10; i++) {
                threadPool.submit(() -> {
                    try {
                        Integer beforeInteger = myData.threadLocalField.get();
                        myData.add();
                        Integer afterInteger = myData.threadLocalField.get();
                        System.out.println(Thread.currentThread().getName() +"\t"+ "before:" + beforeInteger + " after:" + afterInteger);
                    } finally {
                        myData.threadLocalField.remove();
                    }
                });
            }
        } catch (Exception e) {
            throw new RuntimeException(e);
        }
    }
}

class MyData {
    ThreadLocal<Integer> threadLocalField = ThreadLocal.withInitial(() -> 0);

    public void add() {
        threadLocalField.set(threadLocalField.get() + 1);
    }
}
